[SOLVED] AudioProcessorValueTreeState: reset all sliders to default, from code?

Development
1

Hello!
I have a plugin that uses AudioProcessorValueTreeState to manage its state, with a bunch of sliders in the UI.

I’d like to add something like an “INIT” button to reset all sliders to their initial position; each parameter has a default value which is set it in createParameterLayout(), and can be easily recalled by double-clicking the sliders).

But how can I achieve the same result from my code?
Is there any built-in mechanism to do this? I took a look at the docs but couldn’t find what I was looking for.
I tried to manually access my parameters and then call something like

freqParam->setValue (freqParam->getDefaultValue());

but I got an error saying that AudioParameterFloat::setValue is inaccessible.

I got the feeling that I’m trying to reinvent the wheel here. Any thoughts?

Many thanks!!

2

From the documentation of AudioProcessorParameter::setValue:

If you want to set the value of a parameter internally, e.g. from your
editor component, then don’t call this directly - instead, use the
setValueNotifyingHost() method, which will also send a message to
the host telling it about the change. If the message isn’t sent, the host
won’t be able to automate your parameters properly.

I hope this helps.

2 Likes
3

Right… I completely missed that - thanks! :slight_smile:

For the records, after doing this,the next problem was that getDefaultValue is also private so it can’t be accessed; I found some useful tips on this thread and managed to get it working.

1 Like
4

How about this approach? In short: convert the APVTS to XML, manipulate the XML so all current values are set to their default values, then replace the APVTS with the modified XML.

// in this example, we have named the Processor's AudioProcessorValueTreeState object as "parameters"

ValueTree state = parameters.copyState();  // grab a copy of the current parameters Value Tree
std::unique_ptr<XmlElement> tempXml (state.createXml());  // convert parameters Value Tree to an XML object

// iterate through each "PARAM" element in XML, and overwrite values with their defaults
forEachXmlChildElementWithTagName (*tempXml, child, "PARAM")
{
	float defaultValue = parameters.getParameter(child->getStringAttribute("id"))->getDefaultValue();
	child->setAttribute("value", defaultValue);
}

parameters.replaceState (ValueTree::fromXml (*tempXml));
1 Like
5

I use:
parameters.replaceState(ValueTree(Identifier("foo")));
to reset to default state, is this not correct?

6

Ik this is old but I was looking for the same solution as the guy who posted this thread and this worked perfectly for me, so thank you.

7

Cool, glad it was helpful. Note that the forEachXmlChildElementWithTagName macro is now deprecated, and the comments note that:

New code should avoid this macro, and instead use getChildWithTagNameIterator directly.

Just something to be aware of, going forward.